Hormones and the Endocrine System

Question 1

Chemical messengers secreted by endocrine glands and transported through the bloodstream are called:
a) Enzymes
b) Hormones
c) Neurotransmitters
d) Antigens

Answer 1

b) Hormones

Question 2

What are the two main types of hormones based on their chemical structure?

Answer 2

Steroid hormones and peptide hormones

Question 3

Hormones bind to specific ____ on target cells, triggering a cellular response.

Answer 3

receptors

Question 4

TF: All cells in the body have receptors for every hormone circulating in the bloodstream.

Answer 4

False. Specific cells have receptors for specific hormones.

Question 5

How does the mechanism of action differ between steroid hormones and peptide hormones?

Answer 5

Steroid hormones can pass through the cell membrane and bind to receptors inside the nucleus, directly regulating gene expression. Peptide hormones bind to receptors on the cell surface, triggering a signal transduction pathway that relays the message into the cell.

Question 6

What is the name of the regulatory system where the hypothalamus, pituitary gland, and target glands interact to control hormone release?

Answer 6

Hypothalamic-pituitary-axis (HPA axis)

Question 7

Negative feedback mechanisms are crucial for regulating hormone release. Explain how this works using the example of blood sugar regulation.

Answer 7

When blood sugar levels rise above a set point, the pancreas releases insulin to lower them. As blood sugar levels decrease, the negative feedback loop stops insulin release and may even trigger glucagon release to restore homeostasis.

Question 8

Many hormones exhibit a ____ effect, meaning a low concentration can have a stimulatory effect, while a high concentration can have an inhibitory effect.

Answer 8

biphasic

Question 9

What part of the brain is responsible for releasing hormones that stimulate the pituitary gland?

Answer 9

Hypothalamus

Question 10

The pituitary gland is often referred to as the “master gland” because it produces hormones that regulate the function of other endocrine glands. Which of the following hormones is NOT produced by the pituitary gland?
a) Thyroid-stimulating hormone (TSH)
b) Follicle-stimulating hormone (FSH)
c) Insulin
d) Growth hormone (GH)

Answer 10

c) Insulin. Insulin is produced by the pancreas.

Question 11

The thyroid gland produces thyroid hormones (T3 and T4) that regulate ____ and ____.

Answer 11

metabolic rate, growth and development

Question 12

TF: Calcitonin, a hormone produced by the thyroid gland, helps regulate calcium levels in the blood.

Answer 12

True

Question 13

How do the parathyroid glands and the thyroid gland work together to maintain calcium homeostasis?

Answer 13

Parathyroid glands release parathyroid hormone (PTH) when blood calcium levels drop. PTH stimulates bone resorption, increases kidney reabsorption of calcium, and activates vitamin D to enhance calcium absorption from the gut. The thyroid gland’s calcitonin has the opposite effect, lowering blood calcium levels if they become too high.

Question 14

The adrenal glands are located on top of the kidneys and produce two main types of hormones: glucocorticoids and ____.

Answer 14

catecholamines (epinephrine and norepinephrine)

Question 15

The hormone epinephrine, also known as adrenaline, is released by the adrenal medulla in response to stress and prepares the body for a “fight-or-flight” response. Which of the following effects is NOT associated with epinephrine release?
a) Increased heart rate and respiration
b) Elevated blood sugar levels
c) Dilation of blood vessels in the digestive system
d) Increased sweating

Answer 15

c) Dilation of blood vessels in the digestive system. Blood vessels constrict in the digestive system to divert blood flow to muscles during fight-or-flight.

Question 16

The pancreas is both an exocrine gland (producing digestive enzymes) and an endocrine gland that releases the hormones ____ and ____ to regulate blood sugar levels.

Answer 16

insulin, glucagon

Question 17

TF: Testosterone is a sex hormone produced in the testes of males and plays a role in sperm production and development of male secondary sex characteristics.

Answer 17

True

Question 18

What hormone is produced by the ovaries in females and stimulates the development of female secondary sex characteristics and egg maturation?

Answer 18

Estrogen

Question 19

Diabetes mellitus is a condition characterized by:
a) Excessive insulin production
b) Insufficient insulin production or insulin resistance
c) Overactive thyroid gland
d) Deficiency of growth hormone

Answer 19

b) Insufficient insulin production or insulin resistance

Question 20

Goiter, a swelling of the thyroid gland, can be caused by a deficiency of ____, a mineral essential for thyroid hormone production.

Answer 20

iodine

Question 21

TF: Acromegaly is a condition caused by excessive growth hormone production in adults, leading to enlargement of the hands, feet, and jaw.

Answer 21

True

Question 22

How can chronic stress affect the endocrine system and potentially contribute to health problems?

Answer 22

Chronic stress can lead to the prolonged release of cortisol (a glucocorticoid) from the adrenal glands. This can suppress the immune system, increase blood sugar levels, and contribute to weight gain, high blood pressure, and other health issues.

Question 23

Testosterone can influence aggressive behavior in some animals. What is the term for hormones that influence behavior?
a) Neurotransmitters
b) Behavioral hormones
c) Releasing factors
d) Target hormones

Answer 23

b) Behavioral hormones

Question 24

Oxytocin is a hormone produced by the hypothalamus and released from the posterior pituitary gland. It is associated with?

Answer 24

Love, bonding, childbirth, and lactation

Question 25

Seasonal affective disorder (SAD) is a mood disorder that can be linked to fluctuations in ____ levels due to changes in daylight hours.

Answer 25

serotonin

Question 26

TF: Estrogen and progesterone play important roles in regulating the menstrual cycle in females.

Answer 26

True

Question 27

How do hormones and the nervous system interact to influence complex behaviors like hunger, thirst, and sleep-wake cycles?

Answer 27

The nervous system detects internal cues (e.g., low blood sugar) and sends signals to the hypothalamus. The hypothalamus then releases hormones or stimulating factors that influence hormone release from other glands, ultimately regulating these behaviors.

Question 28

What is the circadian rhythm, and how is it influenced by hormones like melatonin?

Answer 28

The circadian rhythm is the body’s internal clock, controlling sleep-wake cycles. Melatonin, produced by the pineal gland, helps regulate sleepiness based on light-dark cycles.

Question 29

During embryonic development, human chorionic gonadotropin (hCG) is produced by the developing embryo and stimulates the:
a) Ovaries to produce estrogen
b) Corpus luteum to produce progesterone
c) Pituitary gland to release growth hormone
d) Thyroid gland to produce thyroid hormones

Answer 29

b) Corpus luteum to produce progesterone

Question 30

Metamorphosis in insects is a complex developmental process regulated by hormones like ____, which triggers the breakdown of larval tissues and the development of adult structures.

Answer 30

molting hormone (ecdysone)

Question 31

TF: Estrogen and progesterone are crucial hormones for stimulating breast development and milk production in females during pregnancy and lactation.

Answer 31

True

Question 32

How do hormones like testosterone and estrogen influence the development of secondary sex characteristics in males and females during puberty?

Answer 32

Testosterone promotes the development of male secondary sex characteristics like facial hair and muscle mass, while estrogen stimulates the development of female secondary sex characteristics like breast development and changes in body fat distribution.

Question 33

What hormone is responsible for stimulating the descent of the testes into the scrotum in male fetuses before birth?

Answer 33

Testosterone

Question 34

What is the main function of the hormone inhibin produced by the gonads (testes and ovaries)?
a) Stimulate gamete production
b) Suppress follicle-stimulating hormone (FSH) release
c) Promote ovulation
d) Increase testosterone production

Answer 34

b) Suppress follicle-stimulating hormone (FSH) release

Question 35

Negative feedback mechanisms are also important in regulating hormone production during the menstrual cycle. Explain how this works with the example of estrogen and FSH.

Answer 35

As estrogen levels rise in the developing follicle, it suppresses the release of FSH from the pituitary gland, creating a negative feedback loop that prevents excessive follicle development.

Question 36

TF: Human growth hormone (HGH) is essential for promoting linear growth and development of bones, muscles, and organs during childhood and adolescence.

Answer 36

True

Question 37

How can environmental factors like nutrition and stress influence hormone production and overall growth and development?

Answer 37

Proper nutrition provides the building blocks for hormone production and tissue growth. Stress can lead to elevated cortisol levels, which can suppress growth hormone production and negatively impact growth and development.

Question 38

What is the term for a group of hormones produced by the placenta during pregnancy that regulate various physiological processes to support fetal development and maternal health?

Answer 38

Placental hormones (e.g., human placental lactogen, progesterone, estrogen)